mickeyw Posted July 20, 2015 Share Posted July 20, 2015 Hi All, Having recently given my 110 CSW a lot more grunt (3.5 on carbs > 3.9 Efi) I'm finding it now goes through the gears rather rapidly. It'll pull away in 2nd and manages 5th quite happily at less than 30 MPH, and seems to be revving quite high by 70. The driveability of the vehicle has completely changed - no more labouring through 3rd and above. Today I towed my 12ft Ifor Williams flat bed, and even with a load of garden foliage on board, I barely knew it was there. Granted the truck was pretty unladen itself. The transfer gearing is currently the standard Defender 1.4:1, and main box is an LT85. Tyres are 255/85R16s (33" tall). So my question is - has anyone with a bigger than original V8 in their 110 opted for a 1.22:1 transfer box, and what did you think of the combination? I don't need to tow as much these days, but the occasional caravan or flat bed do crop up. A quick play on Ashcroft's gearing calculator led me to think the current gearing could be pretty optimum, but I thought I'd ask around. Ashcrofts advise that the ideal gearing gives you approx 2700 RPM @ 70 MPH, although they don't specify what engine that's for, but I assume a Tdi. My current setup gives 2831 RPM @ 70 MPH, so slightly lower geared than their ideal. Changing to 1.22:1 would move to 2453 RPM @ 70 MPH I have read all the debates in the past about gearing changes, and I realise that the 110 is a heavy beast. So I am looking for first hand experiences with V8s (3.9, 4.2, 4.6) fitted to 110s please. Expecting Mr V8Freak to stick his head up Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted July 21, 2015 Share Posted July 21, 2015 You are on a fairly tall tyre, taller than stock with a 255/85. But with a good 3.9 EFI it will pull taller gearing. Depends how much high speed use you want vs acceleration. A 1.22:1 transfer box is certainly doable. But will likely take the edge off the poke. If it was me I probably wouldn't do it. Quote Link to comment Share on other sites More sharing options...
deep Posted July 21, 2015 Share Posted July 21, 2015 I've been in a similar position but possibly can't help as much as I'd like. In my case, I had a Stage One V8 with a fairly tired 3.5 V8. Early on, I changed the transfer gears for Range Rover ones (this being an LT95 box) and it took the sting off the performance but it pulled top gear easily. Later, I also fitted 255/85 tyres. I recall calculating the two changes upped the gearing by a whopping 25%, give or take. For all that, it worked, even with a fairly heavy trailer attached, though I concede it was over-geared. Then I fitted a 3.9. It was an e.f.i. but I took the injection off and ran it on carbs. With that motor fitted, the gearing felt perfect. It would happily pull a firewood trailer up a pretty decent hill at a good speed in top, which strikes me as being an excellent seat of the pants test! Top gear acceleration was really quite good, to the point where I wouldn't have dreamed of changing down to overtake a car on the open road. I'm not sure how the overall gearing stacked up against what you ask for but it must have been close. I'd say go for it. You'll love it if you do any sort of open road work. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 21, 2015 Share Posted July 21, 2015 Aware that you are on an LT85, but my experience with a heavy RRC (2500Kg), I went down to a 1.4 and MUCH prefered how it pulled, I don't tow much that's too heavy, just drives more freely with less labouring than when it was a 1.2. I know its not a 110, but thought I would respond anyways. 1 Quote Link to comment Share on other sites More sharing options...
Oakmaster Posted July 21, 2015 Share Posted July 21, 2015 Ive had a couple of V8 3.5s on the first like 'Deep' above I had a Stage One V8 with a good 3.5 V8. I changed the transfer gears for Range Rover ones (this being an LT95 box) looking for better economy (LOL) and less frantic cruising Later, I also fitted 255/85 tyres. - and then an overdrive (RRC Type this being an LT95 box) this was too much, so I took the RRC transfer gears out and kept the over drive - this was the perfect solution. my 110 V8 3.5 on carbs with an LT 85 (and a GKN overdrive - Not working) seems over geared (even without the overdrive) So Id be interested to hear what the improvement was with the 3.9 Efi Personally Id never be without an overdrive (a matter of personal preference) because it allows you to split the gears, use a lower ratio transfer box, and retain an easy top cruising speed. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 21, 2015 Share Posted July 21, 2015 Just ran the 109 (4.6) through the calculator, seems I'm higher geared than you and not had an issue towing full weight plus a bit : I reckon 2700rpm is a bit too high for a V8 at 70mph. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 21, 2015 Share Posted July 21, 2015 Can't see your graph FF, seems you made it microscopically small somehow? 100px... maybe should have been 1000? I'm at 2,600 @ 70, so pretty close to Ashcroft recommendation, and as I say, it's pretty spritely at that gearing Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 21, 2015 Share Posted July 21, 2015 Oops, how's this: Quote Link to comment Share on other sites More sharing options...
tacr2man Posted July 21, 2015 Share Posted July 21, 2015 i think its more complicated than just saying what revs at what speed, too high a gearing , is more decided by how far you have to have your foot into it , at your normal cruising speed, because if you go a bit high , instead of having a almost foot off cruise you are having to pour more fuel in just to keep rolling , there may well be quite a bit left but you are not at optimum . drag from one vehicle to the next will be a considerable variable , from tyres to aerodynamic. My 110CSW was oe a carb V8 , and later a 3.9i , and I found the gearing perfectly OK in both , but the vehicle had aquired more weight and roof rack etc by the time the 3.9i was fitted so it would suggest that the increase in power was not undergeared due to the extra drag . I have since fitted a 3ltr TDI BMW and had it mapped , and have found it interesting watching the turbo boost guage change at a fixed speed when it is running into a strong headwind ,or not , to see the xtra power required , and am even thinking that there is latitude to pull a higher top gear at lower revs without pushing up the boost requirement , which would affect the fuel consumption , which due to the very low boost to cruise at 60mph has been giving me around 29mpg at the moment . JMHO Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 21, 2015 Share Posted July 21, 2015 Better Projected top speed of 130.... not sure about that Scarily close to my setup, HP22, 1.4, 3.54, 33". What weight are you, FF? (not being rude, honest) Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 22, 2015 Share Posted July 22, 2015 What weight are you, FF? (not being rude, honest) IIRC about 2150kg. tacr2man has a valid point about how much throttle you need at cruise, but I do tend to think RV8's are better (working more efficiently) at lower RPM with a bit of load on than windmilling round at higher RPM, they were certainly not designed to be revvy and LR themselves seem to set cars up in that way. 1 Quote Link to comment Share on other sites More sharing options...
=jon= Posted July 22, 2015 Share Posted July 22, 2015 I can't comment about 3.9's, but I've just swapped a 1.2 for a 1.4 on my megasquirted 3.5 v8, with HP22 auto and 255 85 tyres - with the 1.2 the auto box wouldn't lock up until 57ish mph, and it was right in a torque well (2200rpm ish) - so it'd change into top then fall on it's arse... Given a flat enough road it would slowly pull it's way up to 70+, but it didn't seem happy, and it would drop speed on anything more than a gentle incline... With the 1.4 it will happily sit at 65-70 and only drop back on the steepest of hills... The auto is a bit higher geared than a manual box though (and with less control over when it shifts up), and the tyres are larger and possibly the map needs a tweak, but I definitely prefer it with the 1.4 on... Mickey - if you want to try a 1.2, I've got the old transfer box in the shed (rebuilt with the ashcroft Q gear set) - it needs a new input seal but you are welcome to try it, if you like it we could sort something out (my 'new' 1.4 is whiney so could potentially swap)... Quote Link to comment Share on other sites More sharing options...
mickeyw Posted July 22, 2015 Author Share Posted July 22, 2015 Jon - I went through the same process as you with my old 90. That was 3.9, same size tyres, HP22 (previously LT85) and started with a 1.22:1 trf box. That combo was not great to drive on country roads, as it never got a chance to lock up into top. Motorways were horrible if any hills were involved, even when running empty. I had to pull it into 3rd and rev it like mad - basically the shift points were all wrong. As you say, the auto has a higher top gear than the LT85. Changing to a 1.4:1 ratio made a phenominal difference - the truck became so much more drivable. I'd love to know how much power the auto box sucks out of the set up. The current 110 seems like a rocket compared to the 90. Same engine, same tyres, one manual, one auto. I appreciate engine health and thus available power can vary a fair bit... It's certainly very tempting to try the other ratio. Another possible, albeit more expensive option is to fit an R380, most flavours of which have a higher 5th gear, especially if like Fridge has done a D2 or P38 V8 version is used. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 22, 2015 Share Posted July 22, 2015 That was only a guess, my R380 is a V8 Defender-style one which I didn't spot on their list (did they do V8 R380 Defenders?) and as it was remanufactured by Ashcroft it could have any ratios in there. Quote Link to comment Share on other sites More sharing options...
need4speed Posted July 22, 2015 Share Posted July 22, 2015 If any of the 50th defenders were manual they would be R380. I seem to remember there was a limited number? A bit OT. Sorry. Quote Link to comment Share on other sites More sharing options...
landroversforever Posted July 22, 2015 Share Posted July 22, 2015 50ths were all auto as far as I know? Quote Link to comment Share on other sites More sharing options...
need4speed Posted July 22, 2015 Share Posted July 22, 2015 Apologies. I was thinking about the NAS defenders... Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 23, 2015 Share Posted July 23, 2015 Pretty sure NAS were auto too - they're for 'merkins after all... Quote Link to comment Share on other sites More sharing options...
tacr2man Posted July 23, 2015 Share Posted July 23, 2015 The last of the V8 defenders were r 380 equipped (cost saving measure) as the lt85 was an expensive buy in . I am not certain when they did the swap might be in parts book ? Quote Link to comment Share on other sites More sharing options...
mickeyw Posted July 23, 2015 Author Share Posted July 23, 2015 The last of the V8 defenders were r 380 equipped (cost saving measure) as the lt85 was an expensive buy in . I am not certain when they did the swap might be in parts book ? That must have been NAS models that had the R380. I don't think a V8 Defender was available to the UK market at that time. When LR stopped using the LT85 they used a version of the LT77 with the V8 for a while. (Late 80s, early 90s IIRC). Quote Link to comment Share on other sites More sharing options...
need4speed Posted July 23, 2015 Share Posted July 23, 2015 Yes it was the NAS models. John was right in the respect that the majority of them were autos but the versions that were manual used the R380. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted July 24, 2015 Share Posted July 24, 2015 Plenty of V8 Discos about that used the R380. Shifter housing etc. would need swapped but other than that it should be the same. I hope so anyway as I've got a very dead Disco V8 R380 to go for rebuild and need it done as Defender spec. Quote Link to comment Share on other sites More sharing options...
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